Reference Power Cable Models for Floating Offshore Wind Applications

Abstract

The present study aims to address the knowledge gaps in dynamic power cable designs suitable for large floating wind turbines and to develop three baseline power cable designs. The study includes a detailed database of structural and mechanical properties for three reference cable models rated at 33 kV, 66 kV, and 132 kV to be readily used in global dynamic response simulations. Structural properties are obtained from finite element method (FEM) models of respective cable cross-sections built in UFLEX v2.8.9—a non-linear stress analysis program. Extensive mesh sensitivity studies are performed to ensure the accuracy of the predicted structural properties. The cable’s structural design is investigated using global response simulations of an OC3 5MW reference wind turbine coupled with the dynamic power cable in a lazy wave configuration. The feasibility of the present reference cable in floating offshore wind applications is assessed through a simplified analysis of cable fatigue life and structural integrity analysis of the cable in extreme environmental conditions. The analysis results suggest that the dynamic power cable does not significantly affect the response characteristics of the floating wind turbine in the analyzed lazy wave configuration. Furthermore, a simplified fatigue analysis demonstrates that the proposed cable design can sustain representative environmental loading scenarios and shows favorable dynamic performance in a lazy wave configuration.

Experimental and Numerical Study of Suspended Inter-Array Cable Configurations for Floating Offshore Wind Farm

“…Figure 9 shows the cross-section of the cable proposed by Janocha et al (2024) [20]. Table 5 shows the power cable and buoyancy segment properties proposed by Rentschler et al, 2019 [21], which is the same as Thies et al (2012) [6].…”

The IEA Wind Task 49 Reference Floating Wind Array Design Basis

“…Considering a floating wind array with a power capacity in the range of 300 MW to 1 gigawatt (GW), the array cables would be expected to be 66 kV or 132 kV. Cables rated at 66 kV are already in use for large FOWTs in operation today [31], and data for such cables are available [32]. There is a growing demand for 132-kV cables, and research is ongoing to address the challenges of these higher-voltage cables, especially for dynamic cables where the deflections and loads are greatest [33], [34].…”

“…These values are based on reference dynamic cable models for 630 mm 2 dynamic cable [32] along with relationships to scale the properties to other conductor areas based on manufacturer data sheets and modeling assumptions. Similar properties for static cables are not specified because their specifications do not have an impact on the dynamic response or floating system design.…”

“…For ultimate load analysis of dynamic cables, the main requirement is that the dynamic cable designs are compatible with the extreme motions of the floating system. The two most critical aspects to check for the survivability of the dynamic cable itself are whether the tensions are within the minimum breaking load and whether the curvatures are above the minimum bending radius [32]. These parameters should be known for a given cable product, and appropriate safety factors are dictated by the standards.…”

“…Additional requirements could relate to avoiding clashing or abrasion, such as ensuring that the buoyancy section and its buoyancy modules do not contact the seabed. For fatigue analysis of dynamic cables, bending fatigue tends to be more severe than axial tension fatigue, so special attention is paid to changes in the cable curvature [32], [50].…”